Metabolite Profiling Experiments

The GC-MS metabolite profiling experiments given below are made
publicly available to get feedback from the community. The relative metabolite concentrations
are normalised according to fresh weight (or comparable quantitative data, such
as volume, cell count, etc.) and internal standards (e.g. ribotol). Although these
details are accessible within the GMD, they are not made available on the web site
so far. For these details please refer to the publication. As it is our intention
to increase the breadth GMD’s experiment repository in terms of organisms, organs
and stresses, we actively work on cross experiment normalisation and thus, profile
data and data representation might change in the future without any further notice.
For maximal quality assessment, all experiments are described using the XEML framework (see tree below), while the
GC-MS chromatograms are processed using the TagFinder software.

Metabolomic responses to long-term salt stress in related Lotus species (C)contact: kopka@mpimp-golm.mpg.dedescription: The legume genus Lotus includes glycophytic forage crops and other species adapted to extreme environments, such as saline soils. Understanding salt tolerance mechanisms will contribute to the discovery of new traits which may enhance the breeding efforts towards improved performance of legumes in marginal agricultural environments. Here, we used a combination of ionomic and gas chromatography-mass spectrometry (GC-MS)-based metabolite profilings of complete shoots (pooling leaves, petioles and stems) to compare the extremophile Lotus creticus, adapted to highly saline coastal regions, and two cultivated glycophytic grassland forage species, Lotus corniculatus and Lotus tenuis. L. creticus exhibited better survival after exposure to long-term lethal salinity and was more efficient at excluding Cl- from the shoots than the glycophytes. In contrast, Na+ levels were higher in the extremophile under both control and salt stress, a trait often observed in halophytes. Ionomics demonstrated a differential rearrangement of shoot nutrient levels in the extremophile upon salt exposure. Metabolite profiling showed that responses to NaCl in L. creticus shoots were globally similar to those of the glycophytes, providing little evidence for metabolic pre-adaptation to salinity. This study is the first comparing salt acclimation responses between extremophile and non-extremophile legumes, and challenges the generalization of the metabolic salt pre-adaptation hypothesis.start date: 2007-01-01experiment Id:
747b1c79-3ef5-486f-b5ba-4faf0b0f55e5links: metabolite profileMapMan pathwayXEML experimental descriptionISA-Tab exportTagList Metabolite raw exportTagList Metabolite norm exportTagList Analyte raw exportTagList Analyte norm exportTagList MST raw export

This tree schematises the experimental design
of a single metabolite profiling experiment with the x-axis representing the time
scale. Branches of the tree are used to describe the plant’s environmental condition.
Recorded environmental conditions are either given to describe the general experimental
setup and to support cross experiment comparisons, or to indicate the specific stress
type. A “salt stress experiment” is described using different salt concentrations.
Clicking the nodes of the tree, quantitative environmental conditions (e.g. temperature,
salt concentrations, humidity, etc.) describing the plant’s environment can be inspected
in the right table. Unfortunately, due to the limitations of the current html based
visualisation, the scaling of the tree's branches is not proportional to the real
length of time. Green tagged observation points (OP) represent sampling time points.
Results in the data analysis (see heat map or MapMan links in table on top) correspond
to these observation points. Please note that observation point names (OP1, OP2,
etc.) do not relate to each other. Instead, use the description of the observation
points to identify potential candidates for cross experiment profile comparison.